Fungicidal compositions



Patented Dec. 28, 1948 FUNGICIDAL COMPOSITIONS John W. Heuberger,Newark, Del., assignor to Riihm & Haas Company, Philadelphia, Po, a

corporation of Delaware No Drawing. Application December 2, 1944,

Serial No. 566,395

Claims. (Cl. 16722) This invention relates to agricultural fungicidalcompositions and particularly to a fungicidal composition obtained bymixing a dithiocarbamate with zinc oxide or with materials which, whenplaced in an aqueous solution, produce zinc hydroxide, such as a solublezinc salt and lime.

It has heretofore been known that dithiocarbamates have fungicidalactivity and may be used on living plants to control injury from fungusdiseases. The fungicidal value of such compounds has not, however, beensuiiicient to constitute a practical improvement over the coppercompounds now commonly used as agricultural fungicides.

It has also been proposed in agricultural sprays to use the flocculentprecipitate that isobtained by adding lime and a soluble salt of suchmetals as zinc, manganese, or aluminum to an aqueous solutionorsuspension of an insecticidal or a fungicidal material to aid theadherence of the sprayed material to the foliage of plants. Such uses ofzinc salts and lime have the mechanical effect of improving the stickingof the fungicide and do not increase fungicidal activity.

The object of this invention is to provide an improved agriculturalfungicide that avoids the use of copper and which affords equivalent orsubstantially better protection than that obtained by fungicides basedon copper.

Another object of this invention is to provide an efficient completefungicidal preparation that does not require mixing with materials otherthan water when placed in the spray tank.

These objects'are attained through the discovery that, by mixing adithiocarbamate with zinc oxide or with lime and a soluble salt of zinc,a fungicidal composition is obtained which is not only superior to thedithiocarbamates when used alone but provides better protection andlarger yields of crops than is obtainable with copper fungicides eitherwhen used alone or when used in conjunction with zinc sulfate and lime:It has also been observed that the foliage of plants treated with thecombination are softer and healthier than the foliage of plants treatedwith copper sprays. The combination seems not only to destroy fungusdiseases but, in addition, to st mulate plant growth.

The dithiocarbamates that may be used in the combination are the saltsof dithiocarbamic acids having the formula wherein R represents anorganic group, R represents hydrogen or an organic group, and Mrepresents a salt-forming group. The organic groups in these compoundsmay be acyclic, alicyclic, or aromatic, or R and R together with thenitrogen may form a heterocycle. The saltforming groups may be a metal,an amine, or a quaternary ammonium group. The dithiocarbamates may besoluble in water, such as the sodium, potassium, and calcium salts andsome of the amine and quaternary ammonium salts, or they may beinsoluble or relatively insoluble, such as the copper, iron, zinc, andcadmium salts. The dithiocarbamate portion of these compounds may beobtained by the well known reaction of carbon disulfide upon amines, andthe amines used may be primary or secondary, monoamine or polyamine,aliphatic, aromatic, heterocyclic, or alicyclic. Typical amines that maybe used are monomethylamine, dimethyiamine, cyclohexylamine,dicyclohexylamine, monoethylamine, diethylamine, ethylene diamine,propylene diamine, diethylene triamine, piperidine, piperazine,paraphenylene diamine, benzylamine, benzlymethylamine,phenylmethylamine, aniline, and similarly constituted amines. Compoundshaving a relatively low ratio of carbon atoms to dithiocarbamate groupsare preferred, particu-. larly the aliphatic dithiocarbamates such asmonoand di-methyl dithiocarbamate, monoand di-ethyl dithiocarbamate, andethylene bisdithiocarbamate. polydithiocarbamates of aliphaticpolyamines such as ethylene and similar alkylene bisdithiocarbamates.

0f the soluble zinc salts, the sulfate is preferred but other solublesalts, such as the chloride or nitrate, may be used.

In the preparation of the fungicidal composition, the components may bemixed in the dry state and thus simultaneously added to water in thepreparation of the spray, or the materials may be individually added tothewater and mixed therein. The ratio of each ingredient in the mixturemay be varied considerably and an excessive quantity of any one is morewasteful. of that ingredient than detrimental to the desired result.Very good results are obtained when one and one-half pounds of thedithiocarbamate are mixed with one pound of commercial zinc sulfate andone-half pound of lime and the mixture used in the production of gallonsof spray. The dithiocarbamate may, however, be reduced to one-half poundor increased to four pounds. The zinc sulfate, also, may be reduced toas little as one-eighth pound and the lime to one-sixteenth pound perone and one-half pounds of dithiocarbamate and, while such mixturesappear to be less effective in some respects than the preferred50:33:l'7% ratio, they give substantially better results than thedithiocarbamate used alone.

Of particular value are the.

. 3 When zinc oxide is used in the combination. one pound of oxide andtwo pounds of dithiocarbamate have been found very efiective in 100gallons of spray, but the best ratio and dilution to use may depend uponthe particular circumstances.

The following examples are given to illustrate the practice of theinvention and the results obtainable by its use. The dithiocarbamateused in these tests is disodium ethylene bisdithiocar bamate.

LE 1 G oarnor. or Esau Error on Porsrons In a replicated randomizedblock experiment small plots of potatoes were given seven applicationsof the fungicidal preparations indicated in Table I. The applicationswere made at approximately ten-day intervals over a period beginningwhen the plants were 8-10 inches high and continuing until the potatofoliage died down-normally. Spraying was done with a knapsack sprayer atthe rate 01' 200 gallons per acre. No late blight appeared during theseasonbut early blight was destructive.

Com-nor. or Lars Bazaar on Porsroas Test plots of potatoes replicatedfour times were sprayed with the materials indicated in Table II.Applications were made at the rate of approximately 125 gals. peracreand at weekly intervals except when weather was favorable for blight inwhich period applications were made every four or five days. A total oftwelve applications were made. The results or the tests are shown inTable H. I

Table I2 Per cent Leaves dead from Late Bil lit at Ave" a Material FourReading ates (Ilia/100 gels. of spray) Bu/Acm 1st 3nd 8rd 4th Check(unsprayed)... 81. 1 00. 2 100 100 142. 68 Ditbiomrbamste, 3.... Zincsulfa 1 3.4 9.5 22 223. 17

me Dlthiwarbamate, l. Zinc sulfate, 1 12.1 17.0 58 204.88 Lime, $6Dithiocarbamate, 56.. Zinc sulfate, 1-.- l8. 3 3d. 2 70 201. 22 Lime, )4Yellow cuprous oxide, 1% fine sulfate, 1 3. 4 37. 81 100 180. 58

Yellow cuprous oxide, 1% 8.3 32. 7 88 100 188. 41 Dithiocarbamate, i.2i. 1 04. 2 86 100 173. 77 Ditbiocarbamate, 2. 13. 3 52. 2 85 100 164.62 Dltbiocarbemate, $4 53. 7 69. 6 87 100 160. 00

Table I]! Diseased Folia e at Material Four Reading ates A??? e(Ilia/100 gels. of spray) i i 1st 2nd 8rd 4th 26 Check 0.25 7.00 7.008.20 228.02 Dithiooarbsmate, 2 Zinc sulfate. 1..... 1.06 1.70 2.11 8.10382.28 LimeJ Dithlooerbemate, 4.. 3o linesuatefl 1.08 1.00 2.12 8.150859.25

in Dithiocarbsmate zmcsulmtmlfljflfl 1.58 2.00 2.50 2.00 204.25fgfff'ffff: 2.03 3.40 4.20 5.80 231.55 Dithi0carbamate,2-. 8.33 4.005.00 6.80 277.49, Dithiooarbamete, Zincsulfafefl. 1.42 1.00 an 4.001:22.10

Lime, Me

answers LII s CONTROL OF BLIGHT 0N TOMATO Test plots of tomatoesreplicated three times were treated with the materials indicated inTable HI. A total of seven applications were made at approximatelyweekly intervals. when #1 and U. S. #2 were considered. Results 01' thetest are given in the following table.

During these tests it was noticed that the sprayed plants remained freeof aphis while a moderately heavy infestation which made necessary twoapplications of an Aphicide built up in nearby plots.

EXAMPLE 4 In a test to compare the emciency oi zinc oxide in thecombination in place of zinc sulfate and lime, test plots of potatoeswere treated with the sprays indicated in Table IV, and after fiveapplications at approximately weekly intervals the plants were rated bythe scale of 0-10 on the amount of injury from both early and lateblight. Readings were made on plants in each test and averaged.

Table IV Material (lbsJlOO gals. of spray) figg, gfigfl Dithiocarbamate,2 Zinosulfato, 1.. 2.0 0.8

Dithiocarbamate Zincnxide, l.. 1 Dithiocarbamate, 2"; 3. 6 2.0 Copperfungicide (oheck).... 4. 5 2. l

5. A fungicidal composition adapted for agricultural use comprising from16, to 32 parts of dlsodium ethylene bisdlthiocarbamate,v from 2 ,to

16 parts of zinc sulfate, and from 1 to 8 parts of lime.

JOHN W. HEUBERGER.

genie" 'BEFEBENCES CITED The following references are oi record in thefile or this patent:

UNITED sums PATENTS Number Name Date 1,791,430 Roberta Feb. 3, 19311,972,981 'I'isdale et a1 Sept. 11,1934 2,281,735 Wieder May 5, 19422,290,235 Guy July 21, 1942 2,317,765 Hester Apr. 27, 1943 2,325,720Urbschat et a1. Aug, 3, 1943

